Magnetic switch



Aug. 12, 1958 D. E. comes 2,847,528

MAGNETIC SWITCH Filed Feb. 21, 1955 3 Sheets-Sheet 1 (a 4; l 44 -fl 76.11 11 4; as,

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BY W Aug. 12, 1958 Filed Feb. 21, 1955 D. E. COMBS MAGNETIC SWITCH 3 Sheets-Sheet 3 INVENTOR BWKW 2,847,528 Patented Aug. 12, 1958 United States Patent Ofiice MAGNETIC SWITCH Donald E. Combs, Baldwin Park, Calif. Application February 21, 1955, Serial No. 489,529

18 Claims. (Cl. 200-67) This invention relates to switches and more particularly to switches using magnets for controlling the operation of the switch.

Switches have been developed and built for many years. In spite of the considerable etiort which has been made in perfecting the switches being used, certain disadvantages For example, the switches are inherent in the switches. v require the use of springs to control the movement of a first electrical contact into engagement with a second electrical contact. Springs are disadvantageous since they become fatigued after some use and cause the characteristics of the switch to vary. The springs are also disadvantageous because they limit the speed at which the first contact is able to move into engagement with the second contact. This has been especially troublesome in industrial applications where switches must be operated into on and otf" positions on a recurrent basis.

This invention provides a switch in which no springs of any kind are used. The invention includes a casing and a magnet fixedly positioned within the casing. A coupling member is disposed within the casing in movable relationship to the casing. The coupling carries a magnetizablc armature disposed in contiguous relationship to the magnet. The coupling member also carries a first con tact movable with the coupling member into engagement with a second contact fixedly positioned within the casing.

A button extends through the casing from a position outside of the casing and abuts the coupling member. When the button is depressed, it moves the coupling memher into position for the first contact to engage the second contact. In this position, the armature is still within the attractive influence of the magnet so that the coupling member can be returned by the magnet to its original pcsition when the button is released. By using such an arrangement, a switch having a small size can be inexpensively produced for reliable operation over long periods v of time.

An object of this invention is to provide a switch which does not require the use of any springs.

Another object is to provide a switch utilizing magnetic principles to control the operation of the switch in its on and off positions. 7

A further object is to provide a switch which can be operated on a cyclic on" and 011" basis at a relatively high speed.

Still another object is to provide a switch which can be made inexpensively from a minimum number of components and which can be assembled to form a unit occupying a relatively small space.

A still further object is to provide a switch which main tains substantially constant operative characteristics over long periods of time.

Other objects and advantages will be apparent from a detailed description of the invention and from the appended drawings and claims.

In the drawings:

Figure l is a sectional view of a single-pole, singlethrow switch constituting one embodiment of the invention and including a magnetic armature and an electrical contact movable in a linear direction;

Figure 2 is a sectional view of a single-pole, doublethrow switch constituting another embodiment of the invention, the switch shown in Figure 2 including a magnetic armature and an electrical contact movable in a linear direction;

Figure 3 is a sectional view of a single-pole, doublethrow switch having a pair of magnetic armatures and a pair of electrical contacts movable in a linear direction;

Figure 4 is a sectional view of a single-pole, singlethrow switch which performs the same functions as the switch shown in Figure 1 but which includes a magnetic .armature and an electrical contact pivotable on opposite sides of a fulcrum;

Figure 5 is a sectional view of a single-pole, doublethrow switch including a magnetic armature and an electrical contact disposed in pivotable relationship on opposite sides of a fulcrum;

Figure 6 -is a sectional view of a single-pole, doublethrow switch having a first armature and a first electrical contact pivotably disposed on one side of a fulcrum and having a second armature and a second electrical contact pivotably disposed on the opposite side of the fulcrum;

Figure 7 is a sectional view of a single-pole, singlethrow switch in which an armature and an electrical contact are pivotably disposed on the same side of a fulcrum; and

Figure 8 is a sectional view of a single-pole, doublethrow switch in which an armature and electrical contacts are disposed relative to a magnet in a pivotable arrangement somewhat different from those shown in Figures 4 to 7, inclusive.

In the embodiment of the invention shown in Figure l, a casing 10 made from a suitable material such as plastic or a non-magnetic metal is provided. The casing 10 may have a cylindrical configuration with an outer diameter as small as V1 and an axial length as small as /2". For certain applications. the dimensions of the casing may be even smaller than this. The casing is provided with a socket 12 formed with a first shoulder 14 at an axially interior position and a second shoulder 16 at a position near the axial extremity of the socket. The shoulder 14 is disposed at a position radially interior to the shoulder 16.

A second socket 18 is also formed in the casing 10 at the opposite end of the casing from the socket 12. The socket 18 is defined by a first shoulder 20 at an axially interior position and a second shoulder 22 at a position near the axial extremity of the socket. The shoulder is disposed at a position radially interior to the shoulder 22. The sockets l2 and 18 communicate with each other through a channel 24 extending in an axial direction through the casing.

A cylindrical magnet 26 is positioned in the socket 12 and is disposed against the shoulder 14. The magnet 26 may be made from a suitable material such as that designated as Alnico 5 by the Carboloy Division of the General Electric Company. Such a material is desirable because it provides permanent magnetic characteristics of relatively great intensity for a given amount of material. By using such a material, sufiicient magnetic force can be obtained from a magnet having a diameter of less than /2 inch and an axial length of less than A inch. Furthermore, the use of a configuration such as a cylinder is desirable because it produces a greater working area for a given amount of material than by using other configurathrough the magnet for communication with the socket 12 at an interior position. A button 30 made from a suitable plastic or non-magnetic metal extends through the hole 28 into the opening 12 in depressible relationship to the magnet 26. The button 30 has a relatively thin portion 32 which extends to a position exterior of the casing 10. A cover 34 made from a suitable plastic such as a polyester or from a non-magnetic metal fits snugly into the opening 12 and abuts the magnet 26. The cover 34 has a centrally disposed hole for receiving the extruding portion 32 of the button 30.

The button 30 is positioned at its interior end in contiguous relationship to an armature 3B. The armature 38 may be a disc having a relatively thin axial dimension such as 1;: inch or less. For example, the armature 38 may be a washer with sufficient ferrous content to be magnetizable. The armature 38 is substantially parallel to the interior face of the magnet 26 and is positioned relatively close to the magnet for the imposition of an attractive force by the magnet.

The armature 38 is suitably attached as by riveting to a suitable contact 40 made from a suitable material such as silver or an alloy designated as Faneloy 106 by the Fansteel Company. The contact 40 has a cylindrical portion 42 and a convex portion 44 preferably integral with the portion 42. The cylindrical portion 42 extends through the channel 24 and has a relatively small clearance such as 0.003 inch with the walls of the channel. The cylindrical portion 42 or the rivets may be considered as a coupling member between the armature 38 and the convex portion 44 of the contact.

The convex portion 44 has a somewhat greater diameter than the portion 42 so as to abut the shoulder 20 in one positioning of the contact. At the end axially removed from the shoulder 20, the portion 44 is defined by a curved surface with a relatively great radius of curvature and a high degree of smoothness for reasons which will be described in detail hereinafter. The portion 44 may also be made from Faneloy 106. This material is advantageous because it has a high electrical and heat conductivity and a high resistance to oxidation and to wear.

A cover 48 is adapted to fit in the opening 18 for positioning against the shoulder 22. The cover 48 may be made from a material such as a suitable plastic having good properties of electrical insulation. The cover supports a pair of terminals 50 and 52 respectively having contacts 54 and 56 substantially parallel to the armature 38. These contacts are preferably disposed in symmetrical relationship to the convex portion 44 of the contact 4 40. The interior surfaces of the portions 54 and 56 are preferably rounded so as to establish optimum electrical contact with the convex portion 44 of the contact 40. The contacts 50 and 52 are made from a material similar to the contact 40.

To assemble the switch, the contact 40 is first placed in the socket 18 so that the cylindrical portion 42 extends through the channcl 24. The armature 38 is then suitably attached to the contact 40 as by riveting. The magnet 26 is subsequently inserted into the socket 12 and the button 30 is properly inserted into the hole 28. The covers 34 and 48 are then respectively inserted into the sockets 12 and 18 for abutment against the shoulders 16 and 22.

As a final step, the switch is filled with a suitable inert gas, such as argon or helium at atmospheric pressure. Since the gas is at the same pressure as the atmosphere. very little of the gas leaks into the atmosphere. In this way. the switch can be maintained at optimum performance for long periods of time. By filling the switch with an inert gas, arcing between switch contacts and oxidation of the contacts are prevented.

In the normal positioning of the different members in the switch. the contact 40 is separated from the contacts 54 and 56 by a relatively short axial distance. The button 30 'is also separated from the armature 38 by a relatively short distance or it may be disposed in abutting relationship to the armature. Since the button 30 extends through the casing 10, it may be either manually or mechanically depressed.

When the button 30 is depressed, it presses against the armature 38 and moves the armature 38 away from the magnet 26 against the action of the attractive force exerted on the armature by the magnet 26. This movement is of a sufficient distance for the contact 40 to engage the contacts 54 and 56. A positive engagement is produced between the contact 40 and the contacts 54 and 56 because of the particular material from which the contacts are made and because of the smooth, rounded engaging surfaces.

Since the contact 40 is separated from the contacts 54 and 56 by only a relatively short distance, the armature 38 and the contact 40 are able to move through only a relatively short distance upon the depression of the button 30. Because of its movement through only a relatively short distance, the armature 38 remains separated from the magnet 26 by a relatively short distance. This causes the magnet 26 to exert a relatively large force on the armature 38 for moving the armature back to the magnet. Thus, upon the release of the button 30, the armature moves back to its position contiguous to the magnet 26 such that the electrical continuity between the contact 40 and the contacts 54 and 56 is broken. In this way, the switch shown in Figure l and described above constitutes a single-pole, single-throw switch adapted to establish only a momentary contact upon the depression of the button 30.

The switch disclosed above has several important advantages. It requires no spring of any kind to ensure the making and breaking of contacts. As is well known, springs generally become fatigued after some use, especially in such devices as switches where the switch is constantly being operated to turn the switch on or off." When the springs become fatigued. the operating characteristics of the switch change and thereby affect the operation of components associated with and controlled by the switch.

By eliminating all springs, the switch described above is able to operate for very long periods of time under optimum conditions. These optimum conditions are maintained in part since the contact 40 continues to engage the contacts 54 and 56 at fixed positions over long periods of time. Since the contact 40 engages the contacts 54 and 56 at fixed positions, the time required to close the switch also remains fixed. This is important when the switch is included in circuits requiring a constant frequency of operation.

The switch described above is also advantageous in that it can open and close on a cyclic basis at a fre quency considerably in excess of the switches now in use. This results from the elimination of springs. which require time to build up sufficient forces to open or close the switch. By eliminating all springs, undesirable snap actions are also abolished. These snap actions occur when a movable contact corresponding to the contact 40 dart into engagement with fixed contacts corresponding to the contacts 54 and 56. Such snap actions are undesirable in that they tend to produce excessive wear on the contacts.

The switch constituting this invention is considerably smaller than the switches now in use. This results in part from the minimum number of components which are used. It also results in part from the fact that ,no extra spaces need be allocated to provide for the move ment of such components as leaf springs. Because of the minimum number of components and because of their light masses and compact assembly, the switch described above can withstand high vibrations and shock. This is especially important when the switches are to be used in military equipment and also in airplanes. The small number of components and their easy and compact assembly are also important in minimizing the size and cost of the switch.

The single-pole switch shown in Figure 1 can be also adapted for other uses. For example, the switch can be adapted for use as a single-pole, double-throw embodiment shown in Figure 2. In this embodiment, a casing 100 is provided with a socket 102. A support member 104 made from a suitable insulating material is positioned within the socket 102 at the inner end of the socket and a magnet 106 corresponding to the magnet 26 is disposed in the socket 102 at the outer end of the socket. The support member 104 and the magnet 106 are separated from each other by a relatively short distance for reasons which will be apparent hereafter. The socket 102 is adapted to be closed by a cover 108 corresponding to the cover 34 in Figure l. A button 110 corresponding to the button 30 in Figure 1 extends through holes in the cover 108 and in the magnet 106 in depressible relationship to the casing 100.

The casing 100 is also provided with a socket 112 at the oppodtc end of the casing from the socket 102. The support member 104 is positioned at one end of the socket 112 and a support member 114 made from a suitable insulating material is disposed within the casing at the oppositecnd ol the socket. The support members 104 and 114 are separated from each other by a relatively short distance in the socket 112 for reasons which will become apparent hereafter. The sockets 102 and 112 communi cate with each other as by a hole 116 which extends axially through the support member 104. The socket 112 is adapted to be closed by a cover 120 corresponding to the cover 48 in Figure 1.

A suitable coupling member such as a contact bar 122 extends through the hole 116 into the sockets 102 and 112 and also may extend partially into an axial hole in the support member 114. The contact bar 122 carries an armature 124 in contiguous relationship to the magnet .102 and is in abutting relationship to the button 110.

The armature 124 is positioned in the socket 102 between the magnet 106 and the support member 104.

A contact 126 is attached to the contact bar 116 at a position within the socket 112 and in the space between the support members 104 and 114. The contact 126 is disposed between a first pair of contacts 128 and a second pair of contacts 130. The contacts 128 and 130 are disp-Oscd within the socket 112 in the space between the support members 104 and 114. The contacts 128 extend through the casing 100 and the support member 104 for fixed positioning relative to the casing. contacts 130 are fixedly positioned by the casing 100 and the support member 114.

In the ordinary positioning of the components in the switch, the contact 126 engages the contacts 128 to establish electrical continuity. Upon a depression of the button 110, the contact bar 122 is moved in a direction to interrupt the electrical continuity between the contact 126 and the contacts 128. A further movement of the contact bar 126 brings the contact 126 into engage ment. with the contacts 130.

Even when the contact 126 engages the contacts 130, the armature 124 is still disposed relatively close to the magnet 106. This causes the magnet 106 to exert an attractive force on thearmature 124. Because of this attractive force, the armature moves back to a position abutting the magnet 106 upon a release of the button 110 and the contact 126 moves back into engagement with the contacts 128. In this way, a single pole, doublethrow switch is provided in which electrical continuity is only momentarily established at one of the poles.

The switch shown in Figure 3 illustrates another embodiment of the invention. ing 200. a magnet 202. an armature 204 and a button 206 similar to those described above. The switch also includes a magnet 208, an armature 210 and a button 212 Similarly, the

The switch includes :1 cas- 6 corresponding to the magnet 202, the armature 204 and the button 206. The magnet 208, the armature 210 and the button. 212 are disposed on the opposite side of the casing from the magnet 202, the armature 204 and the button 206.

A contact bar 214 corresponding to the contact bar 122 in Figure 2 is disposed within the casing 200 in abutting relationship to the buttons 206 and 212 at its opposite ends. The contact bar 214 is movable in an axial direction because of its positioning within axial holes in support members 216 and 218 having good properties of electrical insulation. The contact bar 214 carries the armature 204 at one end and the armature 210 at its other end.

A contact 220 similar to the contact 126 in Figure 2 is also carried by the contact bar 214 at an intermediate position between the armatures 204 and 210. The contact 220 is disposed between a first set of contacts 222 and a second set of contacts 224. The contacts 222 and 224 are respectively supported by the members 216 and 218 in fixed positioning relative to the casing 200.

The contact 220 either engages the contacts 222 or the contacts 224 depending upon which of the buttons 206 and 212 is depressed. For example, when the button 206 is depressed. it moves the contact bar 214 so that the contact 220 engages the contacts 224. In this position, the armature 210 is positioned closer to the magnet 208 than the relative positioning between the magnet 202 and the armature 204. This causes the force exerted by the magnet 208 on the armature 210 to be greater than the force exerted by the magnet 202 on the armature 204. In this way, the contact 220 continues to engage the contacts 224 until the button 212 is depressed.

Upon a depression of the button 212, the contact bar 214 is actuated into position for the contact 220 to establish electrical continuity with the contacts 222. In this position, the magnet 202 is closer to the armature 204 than the relative spacing between the magnet 208 and the armature 210. Because of this ditference in spacing, the magnet 202 acts on the armature 204 to retain the contact 220 in engagement with the contacts 222 until the button 206 is again depressed.

In the embodiments shown above, an armature and contacts are moved linearly. Such components may also be moved pivotally to effectuate a proper operation of the switch. For example, the components may be ar ranged in a manner similar to shown shown in Figure 4. The components shown in Figure 4 include a casing 300 and a magnet 302 retained in the casing at one end of the casing. The magnet 302 may be similar to the magnet 26 shown in Figure l.

A suitable coupling member such as a lever 304 is attached at an intermediate position to the casing 300 as at a fulcrum position 306 for pivotal movement relative to the casing. The lever 304 carries at one end an armaturo 308 and at the other end a contact 310. The contact 310 is at a greater distance fromthe fulcrum 306 than the armature 308 so as to produce a balanced operation of the lever 304. The balanced operation of the lever 304 is produced since the armature 308 is heavier than the contact 310. The lever 304 abuts a button 312 at a suitable position such as a position intermediate the fulcrum 306 and the contact 310. The button 312 extends through the casing 300 to a position outside of the casing and is in depressible relationship to the casing.

A pair of contacts 314 are disposed in parallel relationship to each other for engaging the contact 310 in one position of the lever 304. Terminals 316 are connected to the contacts 314. The contacts 314 are shown as being positioned below the contact 310 since the contact 310 is disposed on the bottom surface of the lever 304. However, the contact 310 could be disposed on the top surface of the lever and the contacts 314 could be disposed above the contact 310. Similarly, the magnet 302 could be disposed above the lever 304, especially when the by the lever at one end of the lever.

armature 308 is positioned on the top surface of the lever.

When the button 312 is not being depressed. the lever 304 is pivoted counterclockwise because of the attractive exerted by the magnet 302 on the armature 308. In this position. the contact 310 does not engage the contacts 314. Upon a depression of the button 312, the lever 304 is actuated in a clockwise direction by the button. This causes the contact 310 toswing into engaging relationship with the contacts 314. The contact 310 then has an electrical continuity with the contacts'316 until the button 312 is released. In this way, a single-pole, single-throw switch is provided in which electrical continuity is obtained only during the time that the button 312 is depressed.

By disposing the armature 308 in pivotable relationship to the magnet 302 and at the end of a fulcrum. positive action of the magnet on the armature is insured. This results from the fact that the force exerted by the magnet 302 on the armature 308 is enhanced by the effective length of the lever between the armature and the fulcrum 306 so as to produce a torque. Furthermore. since the lever 304 is balanced on both sides of the fulcrum 306. it can be considered as having no weight. Because of these advantages, the switch can be operated in a relatively fast time to turn it on or off." This is especially important when the switch is to be operated on a cyclic basis.

The embodiment shown in Figure 5 is similar to the embodiment shown in Figure 4 except for the contact arrangement. The embodiment includes a casing 400, a magnet 402, a suitable coupling member such as a lever 404 pivotable as at 406 and an armature 408 carried A first contact 410 is carried by the lever 404 on the bottom surface of the lever and at a position at the opposite extremity of the lever from the armature 408. A second contact412 is carried by the lever 404 on the top surface of the lever at a position directly above the contact 410. Contacts 414 corresponding to the contacts 314 in Figure 4 are positioned below the contact 410 to engage the contact 410 in one position of the lever 404. Similarly, contacts 416 are disposed above the contact 412 to engage the contact 412 in a second pivotal position of the lever. A button 418 extends through the casing 400 in abutting relationship to the lever 404 at a position intermediate the fulcrum 406 and the contacts 410 and 412.

Because of the attractive force exerted by the magnet 402 on the armature 408. the lever 404 is ordinarily pivoted in a counterclockwise direction to bring the contact 412 into engagement with the contacts 416. This electrical continuity between the contact 412 and the contacts 416 is maintained until the button 418 is depresscd. When the button 418 is depressed. it moves the lever 404 in a counterclockwise direction to bring the contact 410 into engagement with the contacts 414. The contact 410 continues to engage the contacts 414 until the button 418 is released. The magnet 402 then acts on the armature 408 to reestablish electrical continuity between the contact 412 and the contacts 416.

In Figure 6, a switch is shown in which a closed circuit can be continuously produced through either a first pair of contacts or a second pair of contacts. The switch includes a casing 500 which supports a suitable coupling member such as a lever 502 at an intermediate position as at 504. A first magnet 506 is fixedly positioned within the casing on one side of the fulcrum 504 and a second magnet 508 is fixedly positioned within the casing on the other side of the fulcrum 504. The casing also supports first and second buttons 510 and 512. 510 extends through the casing 500 in abutting relationship to the lever 502 at a position intermediate the fulcrum 504 and the magnet 506. Similarly, the button 512 is in abutting relationship to the lever 502 at a position intermediate the fulcrum 504 and the magnet 508.

The button The buttons 510 and 512 are disposed in depressible relationship to the casing 500. I

The lever 502 carries an armature 514 at a position contiguous to the magnet 506 for actuation by the magnet. The lever also carries -a contact 516 at the same sIdc of the fulcrum 504 as the armature 514. The contact 516 is adapted to engage a contact 518 fixedly positioned within the casing 500. Similarly, an armature 520 is carried by the lever 502 in contiguous relationship to the magnet 508, and a contact 522 is also carried by tb: lcvcr ca the same side of the fulcrum 504 as the armature 520. In one position of the lever 502, the contact 522 is adapted to engage a contact 524 fixedly positioned within the casing 500.

When the button 512 is depressed, it actuates the lever 502 for pi'roial movement in a clockwise direction. This k' i rCi te contact 522 to engage the contact 524. Because of the pivotal movement, the armature 514 moves c oser to the magnet 506 than the relative spacing between the armature 520 and the magnet 508. This difference in spacing causes the attractive force'exertcd by the magnet 506 on the armature 514 to predominate such thatthe electrical continuity between the contacts 522 and 524 is maintained.

Upon a depression of the button 510, the lever 502 is actuated for pivotal movement in a counterclockwise direction. This pivotal movement produces an engagement between the contacts 516 and 518. It also causes the armature 520 to move relatively close to the magnet 508 such that the magnet 508 has a greater influence on the positioning of the lever 502 than the magnet 506. In this way, the electrical continuity between the contacts 516 and 518 is maintained until the button 512 is again depressed.

The switch shown in Figure 7 operates in a manner similar to that described above for the switch shown in Figure 6. The switch shown in Figure 7 includes a casing 600 and a suitable coupling member such as a lever 602. The lever 602 is supported at one end by the casing as at 604 in pivotable relationship to the casing. The lever carries a first armature 606 on its bottom surface and a second armature 608 on its top surface at a position directly above the armature 606. Contacts 609 and 610 are respectively carried by the lever 602 on the bottom surface and top surface of the lever and at the extremity of the lever.

Magnets 612 and 614 are fixedly positioned within the casing 600. The magnet 612 is positioned directly below the armature 606 and the magnet 614 is positioned directly above the armature 608. Contacts 616 and 618 are also fixedly disposed in the casing 600. The contact 616 is positioned below the contact 609 so as to engage the contact and the contact 618 is positioned above the contact 610 for engagement with the contact 610. Buttons 620 and 622 are supported by the casing 600 in depressible relationship to the casing. The buttons 620 and 622 are in contiguous relationship to the lever 602 at positions respectively below and above the lever and at an intermediate position between the fulcrum 604 and the armatures 606 and 608.

When the button 622 is depressed, the lever 602 is actuated for pivotal movement in a clockwise direction to establish electrical continuity between the contacts 609 and 616. In this position. the attractive force exerted by the magnet 612 on the armature 606 predominates over the force exerted by the magnet 614 on the armature 608. This causes the electrical continuity between the contacts 609 and 616 to be maintained until the button 620 is depressed. Upon the depression of the button 620. the lever 602 is actuated for pivotal movement in a counterclockwise direction to produce an engagement between the contacts 610 and 618. The magnet 614 then acts to maintain the electrical continuity between the contacts 610 and 618 until the button 622 is again operated.

As will be seen, the embodiment shown in Figure 7 operates'in a manner similar to the embodiment shown in Figure 6. However, in the embodiment shown in Figure 7 all of the operative components including the magnets, armatures and contacts are disposed on one side of a fulcrum instead of on both sides of the fulcrum as in Figure 6. In this way. the switch shown in Figure 7 has its operative components arranged in an axially symmetrical relationship in contrast to the radially symmetrical relationship shown in Figure 6.

In the embodiment shown in Figure 8. a switch is provided in which electrical continuity can be only momentarily produced through either first or second contacts. The switch includes a casing 700. preferably cylindrical, which carries a magnet 702 at one end. The magnet 702 has at its inner end an arcuate periphery 704 of concave curvature ior'reasons which will be disclosed in detail hereafter.

A suitable coupling member such as a lever 706 is supported within the casing for pivotable movement on a fulcrum 708, the fulcrum being disposed at the opposite end of the casing from the magnet 702. The lever 760 carries at its free end an armature 710 such that the armature is disposed in contiguous relationship to the magnet 702. The surface of the armature 710 contiguous to the magnet 70?. is provided with a convex curvature 712 corresponding substantially to the concave periphery 704 of the magnet.

The lever 706' also carries a button 716 at a position intermediate the fulcrum 708 and the armature 710. The button 716 extends through opposite walls of the casing 700 in depressible rclaticnship to the casing. Electrical contacts 718 and 720 are supported by the lever 706 at positions intermediate the button 716 and the armature 710. The contacts 718 and 720 are disposed in back-to-back relationship on opposite sides of the lever 706. The electrical contact 718 faces electrical contacts 722 for engagement with the contacts in one pivotal position of the lever 706. Similarly. the electrical contact 720 faces electrical contacts 724 so as to engage the contacts 724 in a second pivotal position of the lever 706. The contacts 722 and 724 are fixedly mounted in opposite walls of the casing 700.

Because of the curved surfaces 704 and 714, the magnet 702 exerts on the armature 710 a magnetic force which has a component disposed radially inwardly. The magnet 702 acts on the armature 7.10 with a radial component of force regardless of the pivotal positioning of the lever 706 and the magnet. This radial component of force causes the magnet 702 to exert a force on the armature 710 for positioning the lever 706 and the armature along an axis intermediate the side walls of the casing 700.

When the button 716 is press-ed to the right in Figure 8. it causes the lever 706 to wing in a counterclockwise direction. This swinging movement of the lever 706 causes the contact 718 to engage the contacts 722. The

contact 718 continues to engage the contacts 722 until the button 716 is released. The magnet 702 then acts on the armature 710 to return the lever 706 and the armature to an axial position intermediate the side walls of the casing 700. ln this positioning of the lever 706, the contact 718 does not have electrical continuity with the contacts 722.

Upon a depression of the button 716 in Figure 8, the lever 706 swings in a clockwise direction such that the contact 720 engages the contacts 724. The contact 720 continues to engage the contacts 724 until the button 716 is released. At such a time, the magnet 702 acts on the armature 710 to interrupt the electrical continuity between the contacts 720 and 724 and to return the lever 706 and the armature 710 to their intermediate positions.

Switches are thus provided in which magnets control the operation of the switches without any necessity for including springs. In all of the embodiments, the operation of the switch is initiated by the depression of a button extending through the casing of the switch. In all of the embodiments, a magnet exerts a force on an armature for returning the switch to the operation which it had before the depression of the armature. In some of these embodiments, the returning force is counteracted by an opposing force for restraining the movement of the, armature. Some of the embodiments are designed to obtain a lineal return of the armature and others to obtain a pivotal return of the armature. Whether -a lineal or a pivotal return of the armature, an electrical contact moves with the armature to affect the electrical operation of the switch.

it should be appreciated that an armature and an electrical contact are movable with each other in all of the cmbcdlmems described above and shown in the drawings. 'l he armature and the electrical contact must be suitably atached to each other to be co-operatively movable. Such attachment may be by a contact bar or a lever as described above or shown in the drawings, or the attachment may be in such other forms as by riveting or welding. In any form, the attachment may be considered as a coupling member" as the term is used in the claims. The term free as applied to the movement of the armatures and the members coupled to the armature for movement relates to a movement which is not controlled by any springs and which is only under the influence of the permanent magnet magnetically coupled to the armature.

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to'be limited only as indicated by the scope of the appended claims.

What is claimed is:

l. A switch, including, a casing, a permanent magnet disposed within the casing. a button extending through the casing in linearly depressible relationship from a position outside of the casing a coupling member disposed within the casing and engageable by the button for movement upon a depression of the button, an armature movable with the coupling member between first and second positions and disposed within the casing in contiguous relationship to the magnet in the first and second positions for attraction by a first pole of the magnet with a sutficient force in the first and second positions of the armature to obtain a movement of the armature toward that pole and a free movement of the armature in accordance with such attraction, a first electrical contact disposed in stationary relationship within the casing, and a second contact movable with the coupling member for engagement with the first electrical contact upon a depression of the button and disposed for movement with the armature out of engagement with the first contact upon a release of the button.

2. A switch, including, a first electrical contact fixedly positioned within the casing. a coupling member disposed within the casing for movement upon actuation, a second electrical contact carried by the coupling member within the casing for movement into electrical continuity with the first electrical contact in accordance with the movement of the coupling member, a permanent magnet fixedly positioned within the casing, a button extending through the casing from a position outside of the casing to a position contiguous to the coupling member for directly actuating the coupling member upon a depression of the button. and an armature made from a magnetizable material and disposed within the casing in contiguous and magnetizable relationship to a first pole of the magnet and carried by the coupling member upon the actuation of the coupling member for movement from the magnet to a position still within the magnetizable influence of the first pole of the magnet for a free movement of the magnet in this position and for a con- 11 tinuous andfull attraction of the armature by the magnet upon the release of the button.

3. A switch, including, a casing, a coupling member disposed within the casing in movable relationship to the casing, a first contact movable with the coupling member, a second contact disposed within the casing for clcctrically receiving the first contact in accordance with the movement of the coupling member, a maguetizable armature freely movable with the coupling member in all positions of the coupling member, a permanent magnet disposed within the casing for magnetically and fully attracting the armature from the same pole of the magnet in the positions of the armature before and after movement of the coupling member with a sufiicient force to obtain a movement of the armature toward this pole. and a button disposed in linearly depressible relationship to the casing and extending from a position outside of the casing to a position within the casing contiguous to the coupling member for moving the coupling member upon a lineal depression of the button.

4. A switch, including, a casing, a permanent magnet disposed in fixed position within the casing, a button extending into the casing from a position outside of the casing and disposed in linearly depressible relationship to the casing, a coupling member disposed within the casing in contiguous relationship to the button for actuation upon depression of the button/a magnctizable armature made from n magnelizable material and carried by the coupling member and disposed in contiguous relationship to a first pole of the magnet before actuation of the coupling member and disposed at a position still Within the attractive influence of the first pole in the magnet upon an actuation of the coupling member and disposed in the depressed and released positions of the button within sufiiciently attractive influences of the same pole of the magnet for a free movement of the armature by this attractive influence toward the pole. a first electrical contact fixedly positioned within the casing. and a second electrical contact disposed within the casing and carried by the coupling member into electrically continuous relationship with the first contact in accordance with the movement of the coupling member.

5. A switch, including, a casing, a first contact fixedly positioned within the casing, a second contact, a coupling member carrying the second contact and linearly movable within the casing through a limited distance between first and second positions for carrying the second contact into or out of engagement with the first contact. a magnetizable armature carried by the coupling member and disposed for free movement within the casing, a permanent magnet disposed within the casing with a first pole in contiguous relationship to the armature for a continuous and full attraction of the armature in the first and second positions of the coupling member with a sufiicient magnetic force to return the armature toward the first pole of the magnet, and a button extending linearly through the casing to a position contiguous to the coupling member for moving the coupling member into an engagement between the first and second contacts upon a linear depression of the button and for moving the armature and the coupling member away from the magnet upon the linear depression of the button.

6. A switch, including, a casing, a permanent magnet fixedly positioned within the casing, an armature disposed within the casing at a position within the full and continuous attractive influence of a first pole of the magnet and movable linearly through a distance for a free movement of the armature in this position and for still disposing it within the full and continuous attractive infiuence of the first pole of the magnet within sufficient distance of the first pole of the magnet to produce a movement of the armature toward the first pole of the magnet, the armature being made from magnetizable material, a first electrical contact fixedly positioned within the casing, a second electrical contact linearly 12 movable with the first electrical contact to a position for establishing electrical continuity with the first electrical contact, and a button extending through the casing in linearly depressihle relationship to the casing for actuating the armature for movement in a direction away from the magnet upon a linear depression of the button.

7. A switch, including. a casing, a permanent magnet fixedly positioned within the casing, a first electrical contact fixedly positioned within the casing, a contact bar movable in a linear direction within the casing, a button extending through the casing in linearly depressible relationship and having a first portion disposed outside of the casing for depression and having a second portion in abutting relationship to the contact bar for linear actuation of the contact bar upon linear depression, an armature di posed within the casing in contiguous relationship to a first pole of the magnet for the imposition of a magnetic force on the armature and disposed within the casing for. a free movement at all positions and carried by the contact bar to a position still within the effective field of the first pole of the magnet upon the depression of the button for the imposition by the first pole of a magnetic field with a'sufficient intensity to produce a movement of the armature toward the first pole of the magnet, and a second electrical contact carried by the armature for engagement with the first electrical contact in a first position of the contact bar and for disengagement from the first contact in a second position of the contact bar.

8. A switch as set forth in claim 7, in which a third electrical contact is fixedly positioned within the casing and in which the second electrical contact engages the third electrical contact before a depression of the button and engages the first electrical contact upon a depression of the button.

9. A switch. including, a casing, a lever pivotably disposed within the casing. a first electrical contact fixedly positioned within the casing. a second electrical contact pivotable with the lever into a position for establishing electrical continuity with the first contact, an armature made from a magnetizable material and disposed for a free movement at all positions and pivotable with the lever, a permanent magnet fixedly positioned within the casing with one of its poles in contiguous relationship to the armature in a first positioning of the lever and with the pole exerting a magnetic force on the armature in a second position of the lever with a sufiicient force to return the armature to its contiguous disposition relative to the magnet. and a button extending through the casing .in linearly depressible relationship to the casing and in abutting relationship to the lever to actuate the lever from its first pivotable position to its second pivotable position upon a linear depression of the button.

10. A switch as set forth in claim 9, in which the lever carries the armature on one side of a fulcrum and carries the second electrical contact on the other'side of the fulcrum at positions along the lever to produce a balanced operation of the lever.

11. A switch, including, a casing, a button supported by the casing with a first portion disposed out of the casing and a second portion disposed within the casing in linearly slidable relationship to the casing upon the imposition of pressure on the first portion, a lever pivotably supported by the casing in abutting relationship to the second portion of the button for pivotal movement by the button, an armature carried by the lever the armature being made from a magnetizable material, a first electrical contact carried by the lever, a permanent magnet fixedly disposed within the magnet with one of its poles facing the armature at distances from the armature in any pivotable position of the armature to exert a force on the armature with a sufficient intensity for pivoting the armature to a position contiguous to the magnet, the armature being disposed in any of its positions for a free movement toward the magnet in accordance with the 13 attractive influence exerted by the magnet, and a second electrical contact fixedly positioned within the casing to establish electrical continuity with the first electrical contact in one pivotable position of the lever.

12. A switch as set forth in claim 11, in which the face of the magnet pole pointing towards the armature is provided with a curvature of concave configuration and in which the face of the armature pointing towards the magnet is provided with a corresponding curvature of convex configuration for the imposition of a force by the magnet on the armature to return the armature to a neutral. position.

13. A switch, including, a casing, a permanent magnet disposed within the casing at one end of the casing, 21 button extending through the casing and through the magnet from a position outside of the casing for linear movement relative to the casing and the magnet upon a depression of the button, an armature made from a magnetizable material and coupled to the button for linear movement with the button and disposed in the depressed and released positions of'the button within sufliciently attractive influence of the same pole of the magnet to obtain a movement of the armature by this attractive influence toward this same pole, a first electrical contact fixedly disposed within the casing, and a second electrical contact coupled to the armature for movement with the armature into or out of electrical engagement with the first electrical contact in accordance with the depression or release of the button.

14. A switch as set forthin claim 13 in which the magnet has at one end a flat face disposed in substantially perpendicular relationship to the movement of the button and in which the armature is a thin plate having a face disposed substantially to the flat face on the magnet for linear movement toward or away from the flat face of the magnet in accordance with the depression or release of the button.

15. A switch, including, a casing, a first permanent magnet disposed within the casing at one end of the casing, a second permanent magnet disposed within the casing at the opposite end of the casing, a first button extending through the casing and the first permanent magnet at one end of the casing in linearly depressible relationship to the casing and the magnet for linear movement relative to the magnet upon a depression of the button, a second button extending through the casing and the second permanent magnet at the opposite end of the casing in linearly depressible relationship to the casing and the magnet for linear movement relative to the magnet upon a depression of the button, first and second magnetizable armatures, the armatures being disposed between the first and second magnets at positions respectively under the magnetic infiuence of the first and second magnets and being connected to each other and coupled to the first and second buttons for linear movements toward or away from their associated magnets in accordance with the depressions of the button and being disposed within the attractive influence of the same pole of their associated magnet in any position for a free movement of the armatures in accordance with a relative attractive force exerted on the armatures by the magnets, first and second electrical contacts fixedly disposed within the casing at opposite ends of the casing, and a third electrical contact carried by the armature for movem .31 into electrical engagement with the first or second electrical contacts in accordance with the depression of the first or second buttons.

16. A switch as set forth in claim 15 in which the third electrical contact is carried between the first and second armatures and in which the armatures are flat plates having flat faces disposed in a direction substantially perpendicular to the movement of the armatures and in which the magnets are provided with flat faces substantially parallel to the faces on the armatures.

l7. A'switch, including, a casing, a permanent magnet disposed within the casing at one end of the casing, a button extending through the casing and the permanent magnet from a position outside of the casing for linear movement relative to the casing and the permanent magnet upon a depression of the casing, an armature made from magnetizable material having properties of low magnetic rctentivity and disposed in the path of movement of the button at a position near the permanent magnet for linear movement away from the magnet upon a depression of the button and to a position still within the attractive influence of the button and without any opposing action by any member for a free return of the armature toward the magnet upon a release of the button, at least a first electrical contact fixedly disposed within the casing toward the end of the casing opposite from the permanent magnet, at least a second electrical contact fixedly disposed within the casing at a position between the first electrical contact and the armature, and a third electrical contact linearly movable with the armature into engagement with the first and second electrical contacts in accordance with the depression or release of the button.

18. A switch as set forth in claim 17 in which insulating members are disposed within the casing and in which the armature and the third electrical contact are carried by a member linearly slidable through the insulating member and in which the magnet and the armature have flat faces substantially parallel to one another.

References Cited in the file of this patent UNITED STATES PATENTS 470,994 Draper Mar. 15, 1892 692,217 Sundh Jan. 28,1902 983,976 Carpenter Feb. 14, 1911 1,394,087 Heinrich Oct. 18, 1921 1,989,277 Jefiery Jan. 29, 1935 2,190,847 Persons Feb. 20, 1940 2,374,435 Jordan Apr. 24, 1945 2,635,157 Flight et al Apr. 14, 1953 2,665,344 Zozulin et a1 Jan. 5, 1954 2,666,112 Nelson Jan. 12, 1954 2,676,221 Malone Apr. 30, 1954 2,688,063 Gomersall Aug. 31, 1954 FOREIGN PATENTS 329,282 Germany Nov. 18, 1920 333,312 Germany Feb. 22, 1921 935,304 France Feb. 2, 1948 Great Britain June 27, 1951 

